Chapter 4 - Polynomials - 4.6 Special Products - 4.6 Exercise Set - Page 276: 11

$9x^2+12x+15$

Using $(a+b)(c+d)=ac+ad+bc+bd$ or the product of $2$ binomials, the given expression, $ (3x+2)(3x+5) $, is equivalent to \begin{array}{l}\require{cancel} 3x(3x)+3x(2)+2(3x)+2(5) \\\\= 9x^2+6x+6x+15 \\\\= 9x^2+12x+15 .\end{array}